From fa71407f3656b0bf65d40e94a20513d56bcf3c61 Mon Sep 17 00:00:00 2001 From: Profpatsch Date: Mon, 26 Mar 2018 17:31:05 +0200 Subject: [PATCH] lib/generators: introduce a sane default for `mkValueString` So far, `mkValueString` defaulted to `toString`, which is a bad match for most configuration file formats, especially because how booleans are formatted. This also improves error messages for unsupported types. Add a test to codify the formatting. --- lib/generators.nix | 26 +++++++++++++++++++++++++- lib/tests/misc.nix | 26 ++++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 1 deletion(-) diff --git a/lib/generators.nix b/lib/generators.nix index 6adf0c2afbc..d1a8f6bf8dc 100644 --- a/lib/generators.nix +++ b/lib/generators.nix @@ -28,6 +28,30 @@ rec { ## -- HELPER FUNCTIONS & DEFAULTS -- + /* Convert a value to a sensible default string representation. + * The builtin `toString` function has some strange defaults, + * suitable for bash scripts but not much else. + */ + mkValueStringDefault = {}: v: with builtins; + let err = t: v: abort + ("generators.mkValueStringDefault: " + + "${t} not supported: ${toPretty {} v}"); + in if isInt v then toString v + # we default to not quoting strings + else if isString v then v + # isString returns "1", which is not a good default + else if true == v then "true" + # here it returns to "", which is even less of a good default + else if false == v then "false" + else if null == v then "null" + # if you have lists you probably want to replace this + else if isList v then err "lists" v + # same as for lists, might want to replace + else if isAttrs v then err "attrsets" v + else if isFunction v then err "functions" v + else err "this value is" (toString v); + + /* Generate a line of key k and value v, separated by * character sep. If sep appears in k, it is escaped. * Helper for synaxes with different separators. @@ -38,7 +62,7 @@ rec { * > "f\:oo:bar" */ mkKeyValueDefault = { - mkValueString ? toString + mkValueString ? mkValueStringDefault {} }: sep: k: v: "${libStr.escape [sep] k}${sep}${mkValueString v}"; diff --git a/lib/tests/misc.nix b/lib/tests/misc.nix index e10aea48e48..5f19dd63f2d 100644 --- a/lib/tests/misc.nix +++ b/lib/tests/misc.nix @@ -207,6 +207,29 @@ runTests { expected = ''f\:oo:bar''; }; + testMkValueString = { + expr = let + vals = { + int = 42; + string = ''fo"o''; + bool = true; + bool2 = false; + null = null; + # float = 42.23; # floats are strange + }; + in mapAttrs + (const (generators.mkValueStringDefault {})) + vals; + expected = { + int = "42"; + string = ''fo"o''; + bool = "true"; + bool2 = "false"; + null = "null"; + # float = "42.23" true false [ "bar" ] ]''; + }; + }; + testToKeyValue = { expr = generators.toKeyValue {} { key = "value"; @@ -249,6 +272,8 @@ runTests { "section 1" = { attribute1 = 5; x = "Me-se JarJar Binx"; + # booleans are converted verbatim by default + boolean = false; }; "foo[]" = { "he\\h=he" = "this is okay"; @@ -260,6 +285,7 @@ runTests { [section 1] attribute1=5 + boolean=false x=Me-se JarJar Binx ''; };